1. Field
The present invention relates to a rechargeable battery.
2. Description of the Related Art
Generally, a rechargeable battery differs from a primary battery in that a rechargeable battery can be repeatedly charged and discharged, while a primary battery is incapable of being recharged. Low-capacity rechargeable batteries are used in small portable electronic devices such as mobile phones, notebook computers, and camcorders, while high-capacity rechargeable batteries are widely used as a power source for driving the motor of a hybrid vehicle.
Typical rechargeable batteries include a nickel-cadmium (Ni—Cd) battery, a nickel-metal hydride (Ni-MH) battery, a lithium (Li) battery, a lithium ion (Li-ion) battery, etc. Particularly, a lithium ion rechargeable battery typically has an operating voltage about three times as high as a Ni—Cd battery or a Ni-MH battery that is widely used as a power supply for electronic devices. In addition, the lithium ion rechargeable battery has been widely used because its energy density per unit weight is high.
In some rechargeable batteries, a lithium-based oxide is used as a positive active material, and a carbon material is used as a negative active material. Generally, batteries are classified into a liquid electrolyte battery and a polymer electrolyte battery depending on the type of electrolyte, and lithium batteries using a liquid electrolyte are called lithium ion batteries while batteries using a polymer electrolyte are called lithium polymer batteries.
In such a rechargeable battery, an electrode assembly and an electrode terminal are sometimes connected via a lead tab. In this case, the lead tab is electrically coupled to the electrode terminal that is provided to penetrate the cap plate by welding or the like.
However, if an abnormality of the rechargeable battery occurs between the cap plate and the electrode terminal, leakage of an electrolyte solution and the like may occur. Accordingly, since a gasket and the like are provided between the cap plate and the electrode terminal to prevent leakage of the electrolyte solution, many parts are required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.